ruler, rulers, rule

Definition:

The term "ruler" is a general reference to a person who has authority over other people, such as a leader of a country, kingdom, or religious group.

In the Old Testament, a king was also referred to with the general term "ruler," as in the phrase, "appointed him ruler over Israel."
God is referred to as the ultimate ruler, who rules over all other rulers.
In the New Testament, the leader of a synagogue was called a "ruler."
Another type of ruler in the New Testament was a "governor."
Depending on the context, "ruler" could be translated as "leader" or "person who has authority over."
The action "to rule" means to "lead" to "have authority over." It is means the same thing as "reign" when referring a king ruling.